The cognitive radio technology is a technology allowing radio communication equipment to use an idle spectrum to perform radio communication without interfering with authorized users in the same band. Nowadays, with spectrum resources being increasingly scarce, cognitive radio is widely spotlighted and researched as a method of improving spectrum utilization. As one of core technologies of cognitive radio, the dynamic spectrum allocation technology becomes a research focus.
In the prior art, from the perspective of network architecture, the dynamic spectrum allocation technology may be based on central control or may be distributed. In the dynamic spectrum allocation based on central control, a central control unit in a network is designed to manage resources of unauthorized bands aggregately, where the unauthorized bands include open bands and open authorized bands. Open bands refer to spectrum resources available to low-power devices (with power lower than 1 w) without authorization, such as industrial scientific medical (ISM, Industrial Scientific Medical) bands, without interfering with devices of other bands; open authorized bands refer to spectrum resources in an authorized band, which are allowed to be used by a device in an unauthorized way without interfering with authorized users, such as television white space (TV WS, Television White Space) band; and authorized bands refer to bands that are not available without a license.
Specifically, the dynamic spectrum allocation method based on central control includes the following steps:
1. A central control unit receives a bandwidth request message sent by a base station, where the request message includes a bandwidth requirement of the base station, transmit power of the base station, and geographic location information of the base station.
2. The central control unit determines current unauthorized idle spectrum resources of the base station according to the transmit power and geographic location information of the base station carried in the bandwidth request message, and determines a spectrum allocation scheme for the base station according to the bandwidth requirement of the base station.
3. If the current idle spectrum resources can meet the bandwidth requirement of the base station, the central control unit sends a bandwidth request response message including the spectrum allocation scheme to the base station.
4. The central control unit receives a bandwidth request confirmation message sent by the base station, and confirms actually used unauthorized band resources.
5. The central control unit updates information on occupation of the unauthorized band according to the received bandwidth request confirmation message.
However, the spectrum allocation scheme determined in the foregoing method may go beyond the radio frequency capabilities of the base station, and the base station may be unable to use unauthorized bands as indicated by the spectrum allocation scheme, which leads to failure of a spectrum allocation algorithm.